docs: def namespace(self, name=None, function=None, recursive=None):
          """
          Returns reference to namespace declaration that matches
          a defined criteria.
  
          """
  
          return (
              self._find_single(
                  scopedef.scopedef_t._impl_matchers[namespace_t.namespace],
                  name=name,
                  function=function,
                  recursive=recursive)
          )